Ice inhibiting assembly for airplanes



ZJGLME 2 Sheets-Sheet 1 Jv @J BY r ATTORN June 6, '1939. E. B. BENSON 1GB I NHIBITING ASSEMBLY FOR AIRPLANES Filed Feb. 26, 1938 l` June 6,1939. E B BENSQN 2,161,242

IG INHIBITING ASSEMBLY FOR AIRPLANES Filed Feb. 2e. 1958 2 sneets-sheet 2 INVENTOR fdWd/"de/zsa/f ATTOR Y Patented June 6, v1939.

PATENT OFFICE ICE INHIBITING ASSEMBLY FOR vAIRPLANES Edward B. Benson, Kansas City, Mo., assignor to The Benson Mfg. Co.

poration of Missouri Kansas City, Mo., a cor- Application February 26, 1938, Serial No. 192,837

6 Claims.

My invention relates to an ice inhibiting assembly for airplanes and more particularly to an assembly for preventing the accumulation of ice on propeller blades of an airplane propeller.

conditions which are conductive tothe rapid formation of ice. When moisture is deposited on a moving plane at or near the freezing temperature, the further lowering of the temperature due l0 to the evaporation of a pcrtion of the moisture causes the remaining moisture to freeze and form ice. The airplane propeller moving through the air at ahigher speed than the plane itself lis particularly subject to the accumulation of ice deu posits when atmospheric conditions are such that ice will form. The deposit' of ice on an airplane propeller blade not only changes the shapeof the propeller blade so as to render it less efficient but results in an unbalancing of the effective weight of the propeller blades. This introduces serious vibration and constitutes an added danger to theI operation of the aircraft.

It has been suggested to provide means for feeding an anti-freezing mixture such as a mix- 26 ture of glycerine and alcohol, and the like, along each blade of the propeller and it has been found that this will prevent the formation of ice deposits on propeller blades, even under severe icing conditions.

The mounting of such arrangements has been a diflicult task. The arrangement is subjected to the high centrifugal speed of the propeller. The propeller blades are constantly vibrating and the combined `vibratory and centrifugal load, as well as the shock loads introduced by starting and stopping, impose a severe strain upon the ice inhibiting assembly. Then, too, the weight of the. assembly must be kept at a minimum, as weight distribution is an important factor in airplane design.

It has been found that devices of the prior art, after operation for a comparatively short period of time, show failure, due to the shock loe-.ding conditions of use. The average length of service of the devices of the prior art has been about one hundred hours.

One object of my invention is to provide an ice inhibiting assembly for airplane propellers, which can be readily mounted without the necessity of aligning and balancing the assembly after mounty ing.

Another object of ymy invention is to provide an ice inhibiting assembly for airplane propellers and more particularly a variable pitch propeller unit which is expeditiously and conveniently re- Airplanes frequently ily through yatmospheric v movable for the servicing of the variable pitch propeller mechanism.

Another object of my invention is to provide an ice inhibiting assembly which is light in weight and simple in construction.

Another object of my invention is to provide an ice inhibiting assembly in which the deleterious effect of vibration of the propeller blades is minimized.

Other and further objects of my invention will appear from the following description.

In the accompanying drawings which form part of the instant specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views;

Figure 1 is an elevation of my ice inhibiting assembly, mounted upon an airplane propeller.

Figure 2 is a sectional elevation of the assen*- bly shown in Figure 1.

Figure 3 is a sectional view taken on the line 3-3 of Figure 2.

Figure 4 is a perspective View of an adapter used in carrying out my invention.

Figure 5 is a sectional view taken on the line 5 5 of Figure 3.

Figure 6 is a sectional view taken on the line 6-6 of Figure 5.

Figure '7 is a bottom plan view of one of the securing means used in my assembly.

Figure 8 is a sectional view taken on the line 8--8 of Figure '7.

Figure .9 is a side elevation of one of the coacting parts of the securing means used in my assembly.

In general, my invention contemplates the provision of adapters of light and strong construction, mounted upon the propeller hub between the propeller blades and adapted to hold a slinger ring construction and a nose spinner construc tion by means of readily detachable spring and cam fasteners whereby the slinger ring and nose spinner are substantially flexibly mounted.

More particularly, referring now to the draw-u ings, an airplane propeller having blades I is mounted on an engine shaft forward of the airplane engine cowling 2. The propeller blades l are supported by propeller hub 3. In the drawings, a variable pitch propeller is shown and the reference numeral 4 indicates a portion of the variable pitch propeller mechanism. It is understood, of course, that the showing of a variable pitch propeller is by way of illustration only, as my invention may be used with any type of airplane propeller. The hub 3 is formed with lugs 5, through which bolts 6 are adapted to pass to hold the two portions of the hub together. According to my invention, I provide adapters such as shown in Figure 4. The: adapters comprise channel members, each having a face 1, which is curved along the radius of a pair of rings 8 and 9, which are adapted to support the slinger ring I and the nose spinner I I, respectively. Flanges I2 and I3 are reinforced by corrugated members I4 and I5, secured to the flanges by rivets I8, thus forming laminated side members of great strength for the weight of material. The side members are provided with openings I1, I8, I9, and 20. Opening vI1 is directly opposite opening I9 and opening I8 is directly opposite opening 2li), and the openings are provided for the reception of the hub bolts 6, as will be readily apparent from reference 'to Figure 5. In the prior art, the point of greatest strain has been at the locus of connection of the adapters to the hub. To strengthen the adapters further, I provide patches 2|, positioned on both sides of respective openings I1, I8, I9, and 20, and riveted to the flanges I2 and I3. The face 1 is formed with lightening openings 22. The edge of the flanges I2 and I3 are turned to form smaller flanges 23 and 24. Each adapter supports an ice inhibiting fluid distributing conduit 25, adapted to receive fluid from the slinger ring and conduct it to the base of the propeller blade I. Respective after ends of fluid distributing conduits 25 are provided with flanges 28, adapted to be secured to the slinger ring.

The face 1 of each adapter is provided with a pair of rows of openings 21. Positioned across each opening 21 is an S-shaped spring 28. 'I'he ends of each spring are riveted to the face 1 of the adapter by respective rivets 29. An S- shaped spring 28xand its securing rivets 29 are shownl on the enlarged sectional view in Figures 7' and It will be observed that the S-shaped spring extends directly across each opening 21. Each spring 28 is adapted to coact with a fasteningv means shown in detail inFigure 9. The fastening means 38 is formed with a body portion 3i and a head 32,the head being provided with a slot 33 adapted to receive a screw driver. The body portion is provided with a cam slot 34 in the form of a highpitch helix. The end of the cam slot 34 lterminates in a seating groove 35. The Width oi' the cam slot 34 is such that the S-spring will enter into the cam slot and, upon rotation of the member the fastening means will be forced downwardly, compressing the spring and -permitting it to seat in the seat 35. If desired, a washer 36 may be placed between the head 32 of the Afastening means and the sheet 9, clamped between the head 32 and the face 1 of the adapter. It is understood, of course, that the fastening means 30 is adapted to be inserted through an opening 21.

When the adapters are in place, secured by respective bolts 8, the faces 1 of respective adapters will lie along the circumference of a circle. A ring 8 is formed as shown in Figure 2' and provided with a plurality of openings, enabling respective fastening members 30 to secure the same to the adapters by the springs in a manner heretofore described. A slinger ring I0 is secured to the ring 8 by means of rivets 31. A ring 9 is adapted to be secured to the adapters by means of fasteners 30 and their coacting springs. A spinner ring II is secured to the ring 9 by means of bolts 38. A rubber shoe 39 may be fitted over are ,secured to the slinger ring openings, being provided for the passage of fluid from the slinger ring through the conduits 25. The arrangement is such that the conduit 25 is progressively farther awayfrom the axis of the propeller so .that

the ilow of the ice inhibiting fluid will be toward the outlet adjacent the propeller blade under the iniiuence of centrifugal force.

It will be observed that each of the adapters is rigidly mounted to the propeller hub and that the slinger ring and nose spinner assemblies are flexibly mounted to the adapters. In this manner, shock loading, due to vibration of the propeller blades, is minimized. The weight of the adapters, per se, is a minor portion of the` load so that the major portion of the load is resiliently supported. The arrangement is such, further, that the nose spinner assembly or the slinger ring assembly may be quickly and readily removed. It is frequently necessary to remove the nose spinner assembly to inspect and service the parts of the variable pitch mechanism. This can be readily done by simply removing twelve fasteners 38, four for each adapter. The nose spinner prevents ice from collecting on the variable pitch mechanism and the rubber shoe prevents ice from collecting on the nose spinner.

In use, the airplane propeller, revolving, ice inhibiting fluid is fed through pipe 40' by any suitable means, as for example; by a pump or by gravity, from any source of supply and is deposited in the slinger .ring I8. Centrifugal force forces the fluid outwardly through pipes 25 for deposit adjacent the base oi.' each propeller blade, and centrifugal force will cause the de-icing fluid to pass outwardly around each propeller blade, preventing ice from collecting thereon. The curved flange at the rear of the slinger rir'rg prevents ice inhibiting fluid from being blown out of the slinger ring by the suction action of the forward motion of the plane. The entire assembly, not counting the fastening means, comprises only ve parts, namely, three adapters, the slinger ring assembly and thenose spinner assembly. In practice, I make the adapters and the rings 8 and 9 of steel, and the slinger ring and the nose spinner of aluminum. A complete assembly for a propeller having a diameter of eleven and one half feet Weighs only fourteen pounds. An assembly of my invention has been in use on transport planes, in winter use under severe icing conditions, continuously for over 220 hours and has shown no signs of failure.

It willbe observed that I have accomplished the objects of my invention. I have provided a nose spinner and slingerring assembly for preventing the formation of ice on airplane propellers in which the entire unit may be readily mounted without the necessity of aligning and balancing the same, after assembly. It is understood, of course, that each adapter is made to weigh the same as the other adapters. The nose spinner is conveniently and expeditiously removable for servicing the variable pitch mechanism. 'Ille aleman adapter construction is of great strength per unit of weight and the entire assembly is extremely light. y

It will be understood that certain features and sub-combinations areof utility and may be employed without reference to other features and sub-combinations.4 This is contemplated by and is within the scope of'my claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is. therefore, to be understood that my invention is not to be limited to the specic details shown anddescribed.

Having thus described my invention. what I claim is:

1. In combination with an airplane propeller having a hub and blades. adapters secured to said hub and extending between said blades, a first mounting ring, spring and cam fastening means for iiexibly securing said first -ring to vsaid adapters. an ice inhibiting huid distributing manifold carried by said nrst ring, a duct adapted to lead ice inhibiting uid into said manifold. ducts carried by said adapters and communicating with saidl manifold for distributing ice inhibiting iiuid from said manifold to points adjacent respective bases of the propeller blades under the action of centrifugal force. a second mounting ring, spring and cam fastening means for flexibly securing said second mounting ring to said adapters.- and a hub cap secured to said secondmounting ring. A

2. In combination with an airplane propeller having a hub and blades, adapters secured to said hub and extending between said blades, a nrst mcimting ring. means for flexibly securing saidmoimtingringtosaidadsptemaniceinhibiting mnd manifoldv carried by said xst mounting ring, means providing communication between said ice inhibiting iluid manifold and points adjacent respective bases oi' the propeller blades, a second mounting ring, means for flexibly securing said second mounting ring to said adapters and s propeller carried by said second vmounting means. l

y 3. In combination with an airplane propeller having a hub and blades, adapters secured to said hub and extending between said blades, an annular ice inhibiting iiuid manifold, means for nexibly securing said ice inhibiting fluid mani-l 4.1msssennmiymmenumswnereinmidA means for flexibly securing said ice inhibiting iiuid manifold to said adapters comprises a plurallty of springs, means for securing said springs to said adapters and a plurality of cam means for coacting with said springs.

5. In combination with an airplane propeller having a hub and blades, adapters, means for rigidly securing said adapters to said hub and between said blades. an ice inhibiting huid Jslinger ring and means for-ilexibly securing said slinger ring to said adapters.

l. An assembly as in claim 5 wherein said adapters comprise channel members having side flanges, corrugated metal sheets secured to said flanges. said iianges and said sheets being provided with openings adapted to receive bolts for seburing said channel members to said h IDWARD B. BENSON.

propeller 

